The current study investigated the willingness of the adult Hungarian population to get a COVID-19 and seasonal influenza vaccine, identified factors that influence vaccine acceptance, and explored the relationship of keywords associated with a COVID-19 vaccine. In this chapter we will first discuss the implications of our findings regarding COVID-19 vaccine hesitancy, then seasonal influenza vaccine hesitancy, then the relationship between the two types of vaccine, and finally, how the keywords were used to describe COVID-19 vaccination.
While only 48.2% of the adult Hungarian population was willing to get a COVID-19 vaccination in our study, this ratio in the United States was between 56.0-68.6% [21,22,23, 43], 56.6% in Italy , 57.7% in Greece , 65.4% in Japan , 66% in Turkey , 72.9% in Finland , between 76.0-77.6% in France [29, 30, 33], 79.8% in Canada  between 81 and 86% in Australia [31, 32], 83% in the United Kingdom , 83.3% in Malaysia , and 83.8% in China . However, in Middle Eastern countries the acceptance rate was lower with 21.4% in Lebanon , 35.9% in Syria , 44.7% in Saudi Arabia , and 46% in Egypt . The differences between the countries in regard of COVID-19 vaccine acceptance could be a reflection of how much the citizens trust information from government sources, thus, clear and accurate communication is required by government agencies when dealing with this issue .
The unfavourable result regarding the Hungarian population was also prevalent in the report of the European Commission published in December 2020, in which of the 27 member states of the European Union only Bulgaria (34%) and Slovenia (33%) had a higher rejection rate for the COVID-19 vaccination than Hungary (32%) . In this same report, only 49% of the Hungarians were willing to get this vaccination at some point in the future. This means that no meaningful change happened between the survey of which this study was based on and the European Commission’s 2020 report.
By mid-April 4,326,000 people had registered for a COVID-19 vaccine on the official Hungarian registration website, which was 50.6% of all the adult population within the country . This indicates that the data gathered on 2020 August predicted those taking action to get a COVID-19 vaccine very accurately.
Female participants were less willing to get a COVID-19 vaccination, although no significant difference was observed. With the exception of one American and one Malaysian research [22, 35] all other studies found this observation to be significant [21, 25, 27, 30,31,32,33,34, 36,37,38,39,40].
Furthermore, the association between age and the willingness to get a COVID-19 vaccination is unclear. While according to many studies [21, 32, 35, 38, 39] higher age was significantly associated with vaccine hesitancy, other researches came to the opposite conclusion [25, 31,32,33]. The results of our study are similar to the findings of an American and Canadian studies in which a J-shaped curve described the association between age and the willingness to get a COVID-19 vaccination [22, 34]. It is more or less obvious that the ageing population has been the most endangered risk group during the first wave of the pandemic in Hungary. On the contrary, the younger population survived the SARS-CoV-2 infection with light symptoms or no symptoms at all, and the long-term complications were not known in August 2020. Thus, the data reflect the public opinion on COVID-19 at the time of the study.
The impact of the level of education on the willingness to get a COVID-19 vaccine is also ambiguous. Three American, a French, a Canadian and a Saudi Arabian study found that having a higher education significantly increases the chance that the respondent will be more willing to get a COVID-19 vaccine [21,22,23, 33, 34, 39]. Two other French and an Egyptian study got the same results, but the difference was not significant [29, 30, 40]. In the Australian, Malaysian and Syrian studies education level had no impact at all [32, 35, 38]. On the other hand, in Turkey and in Greece having a higher education lowered the willingness to get the vaccine [25, 27]. In our study having a higher education significantly increased the willingness to get a COVID-19 vaccine when compared to those having only secondary education, but this difference was not significant when compared to those with primary education.
According to our results living in the capital city of Budapest or in a village was associated with a higher willingness to get vaccinated against COVID-19 compared to those living in any other city in Hungary. Around the summer of 2020 most confirmed COVID-19 infections in Hungary were registered in Budapest, which was widely reported by the media. The fear of getting this infection could have influenced the willingness to get the vaccine in the capital. The reason why those living in villages were more open to getting the vaccine compared to those living in cities remains an enigma.
Better financial status was consistently associated with a significant increase in the willingness to get a COVID-19 vaccine [22, 23, 29, 30]. Although in our study those who stated having the best financial status were also those who were most keen to get a COVID-19 vaccine, still no significant difference was found when comparing the answers to the other categories of perceived financial status.
Overall, due to the differing methodology used in the studies it is challenging to make a firm recommendation on which group should be focused more on when addressing COVID-19 vaccine hesitancy. This, highlight the importance of a unified methodology, in which both the sampling method, confounding factors and statistical analyses should be standardized. Nevertheless, based on our results we recommend to Hungarian policy makers to focus more on the 40-59 aged population with secondary degree living in a city outside of Budapest.
Regarding seasonal influenza vaccination, of the adult Hungarian population only 25.7% were open to get this type of vaccine, which is far lower than the 51.8% of adults living in the United States who actually got vaccinated in the 2019/2020 year . The willingness to get the seasonal influenza vaccine was more favourable among those who are 60 years old or older (38.3%), which is a considerable increase from the 24.1% of Hungarians older than 64 getting the vaccine in 2018 ; however, it is not near the recommendation of the World Health Organization, stating that at least 75% of the adults older than 64 should get this vaccine .
Despite the fact that the findings are in many cases contradictory, most studies investigating the factors influencing the willingness to get the seasonal influenza vaccination found that being female, older, more educated, and wealthier decrease vaccine hesitancy . In our study education and perceived wealth showed a similar pattern, but no significant differences were observed. Surprisingly, females were more reluctant towards seasonal influenza vaccination, albeit not significantly. Similarly, as with the willingness to get a COVID-19 vaccine, when comparing the oldest group with the middle-aged groups, the willingness to get a seasonal influenza vaccine was significantly higher among the oldest groups; however, this significant value was absent when comparing them to the youngest group, suggesting that there is a J-shaped curve as well.
When comparing COVID-19 and seasonal influenza vaccination acceptance with one another, our findings is similar to the studies conducted in the United States and in Italy [43, 44]. A COVID-19 vaccine is much more accepted compared to a seasonal influenza vaccine. Our analysis highlighted that this observation is true, regardless how we stratify the sample based on the demographic data and perceived income. This shows that the citizens are more open to a vaccine that is related to a serious pandemic and this reaction is uniform through the population. Furthermore, the acceptance of one type of vaccine significantly predicts the acceptance with another, which is in synch with previous studies that shown that having the last seasonal influenza vaccine increases the willingness to get a COVID-19 vaccine [39, 45, 46]. Thus, the overall results suggest that a similar strategy could be utilized to increase the acceptance of getting a COVID-19 vaccine among the general population as for a seasonal influenza vaccine [58, 59].
When analysing the categorical keywords inferred from the free text input from the participants, ‘mistrust’ was the most common category when describing a COVID-19 vaccination. A study conducted in the United States found that ‘mistrust’ (lack of trust) was the second most common reason for rejecting the idea to get a COVID-19 vaccine . A systematic review investigating the relationship between trust and vaccine hesitancy in general had also concluded a strong reversed association between these  and studies investigating COVID-19 vaccine hesitancy also emphasize the importance of trust in order to increase acceptancy rates [61,62,63]. In order to improve trust, governments must utilize clear and accurate communication when addressing any information regarding the disease or vaccination .
Similar to the various demographic grouping and the perceived financial status, the willingness to get a COVID-19 vaccine was always more favourable than getting a seasonal influenza vaccination regardless of what kind of words were used, with the exception of ‘fear’, to describe a COVID-19 vaccination. This reinforced the notion that a similar strategy could be utilized to impact vaccine acceptance for both type of vaccines [58, 59].
The word co-occurrence network analysis based on the raw free input text given by the participants showed noteworthy differences between participants who were willing to be vaccinated against COVID-19 and those who were not intending to get a COVID-19 vaccine. The word network for the former group was centred around ‘safety’, ‘defence’, ‘protection’ and ‘health’, and consisted of words with mostly positive sentiment. In contrast, the network for the latter group was organised mainly around ‘uncertainty’, and the majority of the nodes corresponded to words with negative connotations. A previous study conducted in Saudi Arabia demonstrated that holding positive beliefs significantly increase the chance of COVID-19 vaccine acceptance . Therefore, albeit with a different approach, we got the same results.
Finally, this study has some limitations worth mentioning. For example, when narrowing the sample size to those answering each vaccination questions the distribution of the education level changed considerably. However, this reduction was necessary for comparative purposes. Thus, the sample used in the statistical analyses was not representative in this regard. Another noteworthy limitation is that the survey was conducted in August 2020. During that time, there were only hopes for a possible a COVID-19 vaccination, thus, the citizens stated their intention based on a vaccine that not yet existed. There are currently various approved COVID-19 vaccines that the citizens can get [8,9,10,11], and a study has already demonstrated that there is preference based on which country a particular vaccine was produced . Further limitation worth mentioning is that many important questions that can influence the willingness to get any form of vaccination were not included [41, 58].